What was the most common weed problem for North Dakota sunflower producers this past year? How about insects? And how do these concerns compare with those of Kansas growers?

Answers to these and several other production questions have been tallied in the 1997 grower survey on insecticide and herbicide use in Kansas and North Dakota. The preliminary report was released this month by authors H.A. Lamey and J.L. Luecke of North Dakota State University.

What follows are summaries of the producer replies received in several categories. The mail survey also included questions on additional topics, such as herbicide and insecticide application rates, which are not included in this magazine summary. Complete survey results will be included in the proceedings of the 1998 NSA Sunflower Research Forum, to be published this spring.

• Planting Dates — In North Dakota, over half (53.3 percent) of respondents planted their oil sunflower crop between May 11 and May 31, with three-fourths (77.8 percent) planting their confection crop during the same period. All planting was completed by June 10.

Kansas respondents planted 40.9 percent of nonirrigated oil-type ’flowers and 53.3 percent of irrigated oils between June 1 and June 20. Forty percent of irrigated oils and 13.6 percent of nonirrigated oils were seeded in July.

• Yield — Kansas respondents said 30.1 percent of their acreage yielded between 751 to 1,000 pounds; 23.3 percent yielded 1,001 to 1,250 pounds; 13.5 percent, 1,251 to 1,500 pounds; and 15 percent, 1,501 to 1,750 pounds per acre. Among North Dakota respondents, 19.9 percent of acreage yielded between 1,001 and 1,250 pounds; 29.4 percent ran between 1,251 and 1,500 pounds; another 18.5 percent yielded 1,501 to 1,750 pounds and 12.5 percent yielded in the range of 1,751 to 2,000 pounds of seed per acre.

• Worst Weed Problem — Redroot pigweed constituted the single most troublesome weed on 26.2 percent of Kansas respondents’ acreage, followed by Russian thistle (24.4) and kochia (17.6). For North Dakota respondents, foxtail had the dubious top ranking (28.5 percent), followed by wild mustard (19.6), Canada thistle (18.9) and cocklebur (9.1).

• Herbicides Used — Spring-applied Prowl was used on nearly half (45.3 percent) of Kansas respondents’ acreage, followed by spring-applied trifluralin on 14.3 percent. These data are very similar to those obtained from the 1994 survey.

In North Dakota, spring-applied Sonalan was used on 43.4 percent of respondents’ sunflower acreage, followed by spring-applied trifluralin on 29.3 percent and Assert on 9.9. The figures for trifluralin and Assert are somewhat higher than in 1994, while those for Sonalan are somewhat lower.

• Cultivation — Row cultivation was used by Kansas respondents on 41.1 percent of their planted sunflower acreage, with a rotary hoe on just 1.5 percent. In North Dakota, row cultivation was used on nearly two-thirds (64.5 percent) of respondents’ acreage and a rotary hoe on 2.6 percent.

Most growers used just one row cultivation (93.2 percent in Kansas; 85.2 in North Dakota). Two cultivations were used by 6.8 percent of Kansas respondents and 19.1 percent of North Dakotans, with a small number (1.6 percent) of North Dakotans cultivating three times.

• Worst Insect Problem — For Kansans, the stem weevil was the most troublesome sunflower insect in 1997 (35.7 percent of acres), followed by sunflower head moth (33.2 percent) and grasshoppers (11.9). In North Dakota, the sunflower beetle topped the list (59.1 percent of acreage), followed by the sunflower midge (13.1) and stem weevil (6.0).

• Most Common Insecticides Used — Parathion was applied to 17.5 percent of Kansas respondents’ acres last year, followed by Warrior (11.9), Furadan (9.1), Lorsban (6.5) and Asana XL (3.5 percent). Kansas respondents used more ethyl parathion than methyl in 1994, but that pattern was reversed in 1997.

Asana XL went on 41.8 percent of North Dakota respondents’ sunflower acreage in 1997, followed by Warrior (15.2) and parathion (0.9). The minimal use of parathion compares to 13.8 percent in the 1994 survey.

Most insecticide programs consisted of a single treatment, with three-fourths of the Kansas acreage and more than half (53.5 percent) of the North Dakota treated acreage handled via aerial application.